Industrial truck



July 7, 1931. l E. J. ABBE INDUSTRIAL TRUCK Filed Sept. 19, 1927 3Sheets-Sheet l gne wkn awn/M4 am wmwwwzw y 1931. E. J. ABBE I 1,813,595

INDUSTRIAL TRUCK Filed Sept. 19, 1927 s Sheets-Sheet 2 alikoznew July 7,1931. i E. J. ABBE 1,813,595

INDUSTRIAL TRUCK Filed Sept. 19, 1927 3 Sheets-Sheet s $460M M I 1@a/Zw, MMAMM'JS. 41W

Patented July 7, 1931 UNITED STATES EQE - EDWARD J. ABBE, OF CLEVELAND,OI-ITO, ASSIGNOR TO THE ELWELL PARKER ELECTRIC COMPANY, or cnnvnnnnn,01110, A conroianrron or cure INDUSTRIAL TRUCK Application filedSeptember 19, 1927. Serial No. 220,486.

This invention relates particularly to an improvement in industrialtrucks. The essential objectis to provide a practical and eflicientsafety mechanism in connection with a load lifting carriage on atrackway, which mechanism will operate to check downward movement ofthecarriage in the event of breakage or temporary disability of thelifting mechanism.

A more specific object is the provision of a simple and efficientfriction brake safety device on the load lifting carriage of anindustrial truck.

In the use of industrial trucks having a cablehoist and load carrieradapted to raise a load from the ground and place it upon a platform orshelving, it often happens that the operatorafter placing the load onsuch platform pays outthe cable to some extent before withdrawing theload carrier from contact with the platform. Also, in removing a loadfrom such platform or shelving, he sometimes pays out the cable beforethe load carrier is clear of the shelf or platform. The net result ineither case is to allow the carrier and sometimes the load to drop for aconsiderable distance before the slack in the cable is taken up. Thissometimes snaps the cable and if there is no mechanism to stop thedownward movement of the carrier, the load falls clear to the ground andconsiderable damage may re, sult, both to the load and to the truckmechanism. My invention contemplates in part the elimination of suchpossibilities.

Further objects and features of the in vention will become apparent fromthe fol.- lowing description relating to the accompany drawings whereinI have shown my preferred form. The essential characteristics aresummarized in the claims.

In the drawings, Fig. 1 is a side elevation of an industrial truckshowing a vertical trackway and a load lifting carriage mounted thereonfor up and down movement; Fig. 2'is a sectional rear elevation throughportions of the load lifting carriage and showing the safety device inactive position, the section being indicated by the line 22 on Fig. 1;Fig. 3 is a view similar to Fig. 2 but showing the safety mechanism ininactive POSltlOD; Fig. 4 is a longitudmal central cross sectional viewthrough the safety mech- I anism and showing part of thetrackway, asindicated by theline 4-l on Fig. 2; Fig. 5' 1s a cross sectlonalviewtaken along the line 5-5 on Fig. 3;and Fig. 6 is a transverse sectionalview as indicated by the line 6-6 on Fig. 2. p

The embodimentshown comprises a pair of pivoted brake shoes adapted tobear against flanges, or the like, on a trackway, for supporting a loadliftingfcarriagathe shoes being pivoted to the carriage. Each of theshoes has a connection to the lifting mechanism properthrough the blockof a pulley, the: connection comprising arms on the shoes and linksconnecting the arms to the block. A single hoisting cable is shown,which is anchored at one end nearthe top of the trackway, then passesunder the pulley, thence over a sheave near the top of the 'traclrway,and finally to thedrum of a hoisting unit. The hoistingunit may be, ofany suitable form, and may be mounted in any convenlent position on thetruck.

Referring in detail to the drawing, and

first to Fig. 1, an industrial truck body is indicated at 1, provided,with a sub-frame 2 for supporting the body, pairs of driving wheels 8,and steering wheels 4:, one wheel of each pair being shown. Mechanismfor driving the truck may be mounted adjacent the driving wheels 3 andmay be suitably carried on the frame after the manner shown in the priorpatent to Clyde E. Cochran No. 1,399,543 issued December 6th, 1921. Thebody 1 includes a casing for electric storage batteries to furnish powerfor the truck drive, etc, and at the rear side of the body are mountedcontrol members consisting as shown of a steering arm 5, electriccontroller arm 6 and sectional platform members, one section of which isshown at 7 The driver stands on the platform 7 i and shifts his weightfrom one section of the platform to the other in operating the truckdriving mechanism. Standing in this position he is able to manipulateother control members such as 5 and 6. Suitably secured to the front endof the sub-frame 2 is a trackway or frame 10 comprising side members 11and 12 preferably channels, joined together by a cross member 13 at thetop. Other suitable cross members are, of course, provided at thebottom. The trackway is supported in upright position by struts 15 (onebeing shown), extending over the top of the body l nd, r p ctiv y joning he m mb ll and 12 as by gusset plates 16. It is to be understoodthat the details of the truck on which my safety device is to be usedmay be varied within wide limits, since the truck construction so fardescribed was well known prior to the present invention.

The load lifting carriage is mounted to run up and down on the framemembers 11 and 12 which latter members serve as guides.

, The carriage comprises a main frame 20 provided with upper and lowersets of rollers 21 and 22, the set 21 bearing against the rear faces offlanges 23 ofthe upright frame members, and the latter rollers, namely22, hearing against rails 24 mounted on the members 11 and 12.

The main frame has a lower bearing bracket 31 for supporting the shaft32 on which the rollers 22 are mounted, and spaced apart bearingbrackets 33 for carrying a fillitft 34 on which the rollers 21 aremounted.

For. engaging the load, L-shaped carriers 25 are pivoted as at 26 tobrackets 27 secured to the member 20. The legs of the'carriers 25 restagainst an apron 29 on the carriage and the load engaging arms 28 of thecarriers extend forwardly of the truck in posi-' tion to engage beneatha load to lift it when the carriage is drawn upwardly along thetrackway. Usually such loads are placed on stringers, and the arms areadapted to pass the stringers when carried under the load bymanipulation of the truck.

The carriage may be raised and lowered by a cable from a hoisting unit40 which may be of any suitable form. Preferably this unit consists ofan electric motor, the position of which is indicated herein at 41,suitable gearing (not shown), and a hoisting drum, the, position ofwhich is indicated at 42. Secured to the hoisting drum is a cable 48which extends over a sheave 44 carried by a bracket 45 depending fromthe cross member 13 of the frame 10. The cable then extends downwardlyto a pulley 46, connected to the carriage as will be presently shown,and then upward-1y to an anchor 47 on the cross member 13-.

The primary elements of the safety mechanism will now be described; Themain frame member 20 of the carriage supports a cross plate 50, andbetween this cross plate and the member 20. are pivotally mounted twobrake shoe members 51 and 52, the pivots comprisin bolts 54 extendingthrough the cross-plate and into the member 20. The

arms in a straight line.

shoes comprise arcuate portions 56, the outer surfaces 57 of whichgradually recede from the pivots 54 to provide an increasing rippingeflect once the surfaces 57 contact with the trackway. The oppositesides of the shoes have socketed portions 58 which loosely receive theends of a guide bar 59 for a compression spring 60. The ends of thespring rests directly on the members 58 to normally press the $11 .65Qutwardly into engagement with the webs of respective channels 11 and12. The block of the pulley 46 comprises a pair of triangularly-shapedplates 61 62. The plates are connected by the axle 63 of the pulley 46and by bolts 65. The bolts 65 support the upper ends of links 66 asspacers for the plates, and the lower ends of the links are pivotallyconnected as by pins 67 to upwardly extending arms 68 rigid with thebrake shoe members.

In operation, when the carriage is being hauled upwardly 0r graduallylowered by the cable 43, the supporting bolts 65 forthe links, theconnecting pins 67 between the links and arms 68 of the shoes 51 and 52,and the pivot bolts 54 of the respective brake shoes lie in straightlines by reason of slightly compressing the spring 60. This is becausethe weight of the carriage alone is sufiicient to overcome thecompressive strength of the spring. When, however, the pull of the cableis suddenly released as by reason of the cable breaking, or when thecarriage is suddenly free to. move downwardly as by being moved off aplatform with the cable slack, then the arms 68 and the links 66 willassume the relative position shown in Fig. 2 with the shoes in contactwith the trackway by reason of the fact that there is no longer anyforce acting against the spring 60 and tending to hold the links andBecause the single spring 60 acts on both shoes their action will besubstantially simultaneous and uniform. Once the end portions of thebrake surfaces 57 are thus brought into engagement with respectivewebsof the channels 11 and 12, the frictional engagement increases dueto the increasing eccentricity of the shoe surfaces 57. The load carriedon the. arms 28 will, therefore, be arrested and suspended, and will notdrop to the ground in case the cable has been broken, and will not snapthe cable in case it has been, temporarily slack and as above-mentioned,when the cable is mended or the slack taken up, the initial pull on thecable will cause the pairs. of links 66 and? arms 68 to again assumestraight lines as. in Fig. 3, and; the parts will; then remain in thisposition with,- out further attention until again needed. To, releasetheshoes no.- excessive pull; is necessarybecause the shoes simply actas rollers for a little. distance, the bite of the shoes decreasing fromthe first until the shoes are entirely disengaged.

I claim:

1. In a device of the class described, a carriage adapted to sustain aload, a trackway for the carriage, a pair of members pivoted to thecarriage and adapted to engage and disengage respective sides of thetrackway, resilient means physically interposed between and acting inopposite directions on the pivoted members and tending to force themembers into engagement with the trackway, and means to raise and lowerthe carriage, the last-named means being connected to the carriagethrough the pivoted members, and the connection being arranged to opposethe action of the resilient means to normally hold the pivoted membersin inactive position.

2. In a device of the class described, a frame having parallel spacedmembers, a carriage mounted to traverse the frame, a pair of brakemembers pivoted to the carriage and arranged to engage the said framemembers, a horizontally disposed compression spring constantly actingdirectly on both brake members and tending to force the members intoengaging position, and means to raise and lower the carriage, said meansbeing connected to the carriage through the brake members and actingagainst the spring to normally maintain the brake members in disengagingposition.

3. In a device of the class described, upright means for sustaining aload, load engaging means mounted to traverse the upright means, a pairof pivoted members carried on the load engaging means and havingsurfaces arranged to frictionally engage the upright means to preventdownward movement of the load engaging means, a cable for raising andlowering the load engaging means, and means connecting the cable theretoincluding a floating block and links freely pivoted to the block andrespectively pivoted to the said pivoted members for holding the pivotedmembers out of contact with the upright means when the block is liftedby the cable, there being resilient means tending to force the pivotedmembers into contact with the upright means.

4. In an industrial power driven truck, a substantially upright trackwayforming frame .at one end thereof, a load lifting carriage comprising amovable frame with upper and lower reaction members, upper and lowersets of rollers on the respective reaction members arranged to guide thecarriage on the trackway, means to raise and lower the carriage, and asafety braking mechanism supported by the carriage and on which theraising means acts to raise the carriage and said braking mechanismincluding means to engage the trackway in the event the raising andlowering means fails to sustain the weight of the carriage, said lastnamed means being disposed, and acting on the trackway, in a horizontalplane between the reaction members.

5. In an industrial power driven truck, a substantially upright trackwayforming frame at one end thereof, a carriage mounted to be raised andlowered on the trackway, said carriage comprising upper and lowerreaction members and anti-friction members carried thereby respectivelyand guidingly engaging the trackway, means to raise and lower thecarriage, and a safety braking mechanism interposed between andconnected to said last named means and said carriage normally heldinactive by the raising means, said braking mechanismrbeing arranged toengage the trackway in the event saidraising and lowering means fails tosustain the weight of the carriage, and being disposed in a horizontalplane between the reaction members. r

In testimony whereof, I hereunto afiix my signature.

- EDWARD J. ABBE.

